運維之我的docker-docker的網絡管理

        docker引擎十分強大，本身包含了對容器的網絡驅動的支持。默認docker會提供橋接(bridge)和覆蓋網絡(overlay ).

• 橋接：物理網卡和虛擬網卡通過虛擬網絡內的虛擬交換進行橋接，對外通訊。

• 覆蓋網絡：暫時只從官方看到是使用vxlan技術的網絡，swarm使用這種加密網絡會更安全。

1.正常情況下如果你不實用swarm創建覆蓋性網絡需要安裝kvstore服務支持選型，例如consul，etcd和zookeeper

2.一個集群主機連接到kvstore

3.在每個swarm上配置集群引擎的daemon

注意：使用覆蓋性網絡時如果子網重復或覆蓋可能會導致容器無法使用網絡

每個安裝docker的用戶本地都會生成三個網絡如下：

[root@salt-node1 nginx-new]# docker network ls

NETWORK ID          NAME                DRIVER              SCOPE

b60c9e065473        bridge              bridge              local              

a603808ad4ba        host                host                local              

48d3687c03f0        none                null                local   

橋接網卡你docker默認網卡，除非你指定使用別的網絡方式。

[root@salt-node1
nginx-new]# docker run -itd --name=networktest training/webapp
f959f1626b03d965692d0d45f5307c062facac69eff2a33779a50293c35f662e
 
查看橋接網絡內的全部信息
網段，網關，容器IP
[root@salt-node1
nginx-new]#  docker network inspect
bridge
[
    {
        "Name": "bridge",
        "Id":
"b60c9e065473e9d0f8b5eaffc520b681d812e3edd4105cdeba39b5e09bb81ba0",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver":
"default",
            "Options": null,
            "Config": [
                {
                    "Subnet":
"172.17.0.0/16",
                    "Gateway":
"172.17.0.1"
                }
            ]
        },
        "Internal": false,
        "Containers":
{
           
"846953219c6d32025f2ec9b95ea57d50c2f6cc04fbf92047b8a0e5789d623026":
{
                "Name":
"zen_varahamihira",
                "EndpointID":
"d2f6b8fdfa73fc369c5c77465f79f9d7ada17d9d612b5397a3da227a5e133c1b",
                "MacAddress":
"02:42:ac:11:00:02",
                "IPv4Address":
"172.17.0.2/16",
                "IPv6Address":
""
            },
           
"f959f1626b03d965692d0d45f5307c062facac69eff2a33779a50293c35f662e":
{
                "Name":
"networktest",
                "EndpointID":
"3017afc38daac830d872606ffafe5254a408e30e2b10a5c65b0977ba60018c38",
                "MacAddress":
"02:42:ac:11:00:03",
                "IPv4Address":
"172.17.0.3/16",
                "IPv6Address":
""
            }
        },
        "Options": {
           
"com.docker.network.bridge.default_bridge": "true",
           
"com.docker.network.bridge.enable_icc": "true",
           
"com.docker.network.bridge.enable_ip_masquerade":
"true",
           
"com.docker.network.bridge.host_binding_ipv4":
"0.0.0.0",
           
"com.docker.network.bridge.name": "docker0",
           
"com.docker.network.driver.mtu": "1500"
        },
        "Labels": {}
    }
]
[root@salt-node1
nginx-new]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                     NAMES
f959f1626b03        training/webapp     "python app.py"     4 minutes ago       Up 4 minutes        5000/tcp                  networktest
846953219c6d        training/webapp     "python app.py"     25 hours ago        Up 25 hours         0.0.0.0:32768->5000/tcp   zen_varahamihira

從橋接網絡移除指定容器

[root@salt-node1
nginx-new]# docker network disconnect bridge networktest

創建一個自己的橋接網絡

    docker引擎天生再帶橋接網絡和覆蓋性網絡，docker橋接網絡僅限于單機運行，如果出現多機集群就有問題了。這時候覆蓋型網絡更能滿足你的需求，它可以包括多個主機，是一種高級的主題。

docker network create -d [network type]  [network name]

[root@salt-node1
nginx-new]# docker network create -d bridge nginxs-bridge-network
b67220ae9284c802cd48dca1239026b7539c58b97ef19b19ae8b5d7c7ce13d62
[root@salt-node1
nginx-new]# docker network ls
NETWORK ID          NAME                    DRIVER              SCOPE
b60c9e065473        bridge                  bridge              local              
a603808ad4ba        host                    host                local              
b67220ae9284        nginxs-bridge-network   bridge              local              
48d3687c03f0        none                    null                local

查看新的網絡信息

[root@salt-node1
nginx-new]# docker network inspect nginxs-bridge-network
[
    {
        "Name":
"nginxs-bridge-network",
        "Id":
"b67220ae9284c802cd48dca1239026b7539c58b97ef19b19ae8b5d7c7ce13d62",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver":
"default",
            "Options": {},
            "Config": [
                {
                    "Subnet":
"172.18.0.0/16",
                    "Gateway":
"172.18.0.1/16"
                }
            ]
        },
        "Internal": false,
        "Containers": {},
        "Options": {},
        "Labels": {}
    }
]

添加一個容器到指定網絡

      創建一個網絡使得你的web應用在不通的網絡下進行隔離這樣才是安全的。當你第一次運行一個容器的時候你可以把它添加到一個新的網絡。默認情況下兩個橋接網絡的容器是完全不能相互通訊的，要想兩個網絡下的指定容器可以互相通訊會做介紹。

參數：--net=[network name]

[root@salt-node1
nginx-new]# docker run -d --net=nginxs-bridge-network --name db
training/postgres
Unable to find p_w_picpath
'training/postgres:latest' locally
latest: Pulling from
training/postgres
a3ed95caeb02: Pull
complete
6e71c809542e: Pull
complete
2978d9af87ba: Pull
complete
e1bca35b062f: Pull
complete
500b6decf741: Pull
complete
74b14ef2151f: Pull
complete
7afd5ed3826e: Pull
complete
3c69bb244f5e: Pull
complete
d86f9ec5aedf: Pull
complete
010fabf20157: Pull
complete
Digest:
sha256:a945dc6dcfbc8d009c3d972931608344b76c2870ce796da00a827bd50791907e
Status: Downloaded
newer p_w_picpath for training/postgres:latest
4b0bc86f18596e6c24a505a40c759e09c1fd7520a487bf2f278348c641c5240f

查看指定容器的網絡配置

[root@salt-node1
nginx-new]# docker inspect --format='{{json .NetworkSettings.Networks}}'  db
{"nginxs-bridge-network":{"IPAMConfig":null,"Links":null,"Aliases":["4b0bc86f1859"],"NetworkID":"b67220ae9284c802cd48dca1239026b7539c58b97ef19b19ae8b5d7c7ce13d62","EndpointID":"99b9f2f973335447640639e146614ab6f4857b0d1e30f5ed6f9b507f645e137a","Gateway":"172.18.0.1","IPAddress":"172.18.0.2","IPPrefixLen":16,"IPv6Gateway":"","GlobalIPv6Address":"","GlobalIPv6PrefixLen":0,"MacAddress":"02:42:ac:12:00:02"}}
 
[root@salt-node1 ~]#
docker inspect --format='{{range
.NetworkSettings.Networks}}``.`IPAddress``end`' db
172.18.0.2

指定容器可以連接到指定網絡

docker network connect  [network name]  [CONTAINER NAME]

[root@salt-node1 ~]#
docker network connect nginxs-bridge-network db2
 
[root@salt-node1
nginx-new]# docker exec -it db2 bash
root@cf9b593a29bc:/#
ping 172.18.0.2
PING 172.18.0.2
(172.18.0.2) 56(84) bytes of data.
64 bytes from
172.18.0.2: icmp_seq=74 ttl=64 time=0.130 ms
64 bytes from
172.18.0.2: icmp_seq=75 ttl=64 time=0.116 ms
64 bytes from
172.18.0.2: icmp_seq=76 ttl=64 time=0.119 ms